swapping out rear ends

[hillcountryflt]

OK, I just recently cleaned up, painted, replaced axle bearings, etc on the rear end in my 71 f100 (240-cid, 3 spd light duty). I have recently acquired a much better in shape 69 f100 with the same configuration (except long bed and I believe the gearing is different 3.50 to 3.72 - I think).
Would there be any reason I could not swap out? I am going to be using the 69 as a daily driver and the 71 is going into project status, so I could swap out the rear end and then clean up the old one a little more leisurely.

[ToughOldFord]

Same thing, no problem.

[ultraranger]

The ratio would be 3.70:1, instead of 3.72:1. Besides the 3.70s having more pull than the 3.50s, it will also make your speedometer read faster than you are actually going.